There seems to be a bizarre new trend sweeping New York’s theater scene! After Page Six reported last month that an audience member threw up over a mezzanine railing onto theater-goers below at the Broadway play “Grace,” another attendee lost their lunch Sunday, at off-Broadway show “Tribes.” “A woman attending the show got sick in the middle of Sunday’s matinee,” said a spy, adding that in this instance, “at least the woman had the decency to vomit all over herself, unlike that guy at the Paul Rudd play who made such a mess.” While the fellow at “Grace” who hurled as Rudd gave a stirring speech from the stage was tipsy, according to numerous witnesses, this time the woman in question just apparently “had a case of the flu or some such thing,” a source said. However, they added with relief “her seat was on the floor and not in the balcony . . . so the old ‘Grace hurl’ was not an option.” Written by Nina Raine, “Tribes” plays at the Barrow Street Theatre in the West Village.